We hope to be able to evaluate twenty-seven additional patients with myasthenia gravis on this double blind Prednisone-placebo study. Alternate day Prednisone therapy favorably influences the course of myasthenia gravis in some, but not all, patients. The purposes of this study are two-fold. First, to attempt to eliminate psychological factors since neither the patient nor the investigator knows whether the patient is receiving Prednisone or placebo. Secondly, to attempt to determine what factors in myasthenia gravis might be of value in predicting whether the patient will or will not respond to Prednisone, e.g. duration of disease, muscles involved, denervation on EMG, age, and amount of anticholinesterase medication used prior to this study. Thus far, the most valuable objective measurement has been the change in the defect in neuromuscular transmission on repetitive stimulation of various nerves. There appears to be a considerable variation in the dosage of Prednisone administered in myasthenia gravis throughout the country. For us to alter our protocol at this time seems impractical so we plan on continuing to use Prednisone, 100 mg. q.o.d. (or placebo) for the remainder of this project.